FIFA World Cup 2026: Too hot to handle?

"As the FIFA World Cup 2026 is now underway, global attention is focussed on this showcase of elite football. This quadrennial tournament will be the largest in its history, expanding from 32 to 48 participating nations, and will be hosted across North America, with matches staged in the United States of America, Canada and Mexico. As this expanded format results in a greater number of teams, matches and varied range of host cities, the physical and environmental conditions will be challenging.

"Football is a well-documented sport, and the physical demands at the elite level are substantial. During a standard 90-minute match, players typically cover around 10-12 km. Within this, they complete high-speed running efforts approximately every 90 seconds, which account for roughly 10-12 percent of the total distance covered. On top of this, players perform an estimated 1000-1400 discrete movements – including accelerations, decelerations, utility movements and technical actions – occurring roughly every 4-6 seconds. These frequent, explosive movements place a considerable strain on the body.

"Given these demands, fatigue in football is inevitable, but it is also relatively well characterised in the scientific literature, albeit quite multifaceted. It comprises physical, physiological and cognitive/mental fatigue, but if we just highlight the physiological issues, they include a reduction in muscle glycogen (primary energy source), metabolic and cardiovascular stress, muscular strain and damage, dehydration, and an increase in core body temperature. Within football, following periods of sustained high-intensity activity, players commonly experience a short-term reduction in physical output over the subsequent 5 minutes, often referred to as temporal fatigue. This occurs alongside more conventional cumulative fatigue that develops progressively across the match. As a result, players’ capacity for high-speed running and sprinting typically declines over time, with total high-intensity output in the second half significantly reduced when compared with the first half. 

"Now add the heat and humidity of North America. A recent investigation concluded that there is an extreme heat risk, which may necessitate potential interventions to the scheduling of matches at the 2026 FIFA World Cup. Nearly all locations can experience temperatures exceeding the thresholds beyond which some governing bodies would recommend cancellation or postponement. FIFA themselves are including cooling/water breaks within each half, around the 22-minute mark, of every game to ensure consistency across all matches, and thankfully they have made a U-turn on their decision to ban fans carrying their own water bottles to the stadiums. Therefore, careful strategy is required. 

"When players train and compete in hot and/or humid environments, their core temperature and sweat rate rise as they work harder to lose heat. A major factor on our ability to maintain performance in these conditions can be distilled down to demands for blood flow. Whilst we need to increase blood flow to the active muscles to meet the energetic demands for football, during exercise in the heat there is an increased need to regulate temperature that is partly achieved by increasing blood flow to the skin. Working in tandem with increased skin blood flow is an enhanced sweat rate to allow for heat dissipation to the surrounding environment, which in turn may augment dehydration that can exacerbate thermal and cardiovascular strain, further impairing performance. 

"Moreover, as little as a  2 percent loss of body weight due to excessive sweating and fluid loss (commonly achieved in temperate conditions) can result in performance declines due to a decrease in blood plasma volume that can reduce stroke volume (less blood pumped per heartbeat) requiring an increased heart rate, in addition to the elevated core temperature and enhanced perceive effort of exercise. Further, exercise in the heat will increase the reliance on the body’s limited glycogen stores due to an increase in carbohydrate oxidation. In essence, as players core temperature rise it results in the body burning carbohydrate faster. All these issues combined can result in an earlier onset of fatigue, with reductions in high-speed running and sprinting, cognitive ability with slower reactions and impaired decision-making, and importantly increasing the risk of heat-related illness.

"Therefore, strategies to maintain performance and support player health and well-being are paramount. One initial strategy would to be to simply arrive at the desired environment in good time prior to the first match to undergo acclimatisation, although acclimation (artificially mimicking the conditions i.e. heat chamber) could also support the players in the lead up to travel. Adaptations occur quicker with trained athletes, so benefits of acclimatisation can be seen in only a few days. Not only will this improve thermal comfort, but thermoregulatory mechanisms to increase the sensitively of skin blood flow and sweating will be enhanced. Whilst training in your new environment hydration is key. Knowledge of players sweat rate and composition is advantageous as drinks can be individualised to suit each player with regards to volume and electrolyte design. If this is unknown then a crude measure to rehydrate would be to consume 100-150 percent of the weight loss during activity (measure weight loss from pre to post training, and multiply by 1-1.5 to identify the volume to consume).

"As players core temperature rise during exercise, evidence-based heat management strategies are employed. Most strategies will target skin cooling to reduce cardiovascular strain that are more external, but some strategies work internally to lower temperature such as drinking cold fluids and ice-slurry, which can also contain carbohydrate to support additional energy use. External measures may include wearing ice vests on arrival at the stadium and even during the warmups or in any break of activities (such as half-time) - It’s also not too uncommon to see the substitutes wear these. Similarly, the use of ice-towels or ice-collars are typically used around the neck as these can sit comfortably around major blood vessels cooling the circulating blood and reducing the perception of heat.

 "A more contemporary strategy that is rumoured to be in use, is that of a palm cooling device, which supports a reduction in core temperature to improve performance in the heat and can used during periods of rest. Our palms are one of the body's most efficient heat-exchange points and therefore an effective way to cool, as the reverse would be when we wear gloves in the cold to retain heat. Around the training facilities and within the changing room the use of high-powered fans with cooling mists may be incorporated to help cool the players. In addition,  handheld spray bottles with cold water may be used to pre dampen the skin or clothes to support heat dissipation, although this will not likely be needed in humid conditions. Combining these methods at strategic points around training and match day can be valuable tools to support players in preparation, during competition  and recovery. 

"As the excitement builds up and everyone get ready for kick off and the start the World Cup 2026, we may not see continuous explosive action and end to end excitement like we are used to with the Premier league, rather a challenge on how nations prepare and manage the environmental conditions and the intense match demands placed upon them. Those who can maintain a cool head and withstand the heat and demands of competition may come out victorious."